Every COVID-19 test currently (and legally) available in the United States has been approved by the FDA under the agency’s Emergency Use Authorization (EUA)Trusted Source protocol.
The EUA permits the FDA to “allow unapproved medical products or unapproved uses of approved medical products to be used in an emergency to diagnose, treat, or prevent serious or life threatening diseases or conditions caused by chemical, biological, radiological and nuclear threat agents when there are no adequate, approved, and available alternatives.”
That has allowed novel coronavirus tests to quickly hit the market without the research and testing normally required for FDA approval.
To date, the FDA has approved 130 different RT-PCR, antigen, and antibody tests for the new coronavirus.
As the name suggests, these tests look for antibodies made by your immune system in response to an infection with the new coronavirus.
Antibody tests are not diagnostic tests.
“Antibodies can take several days or weeks to develop after you have an infection and may stay in your blood for several weeks after recovery,” according to the Food and Drug Administration (FDA)Trusted Source. “Because of this, antibody tests should not be used to diagnose an active coronavirus infection.”
Antibody tests also aren’t terribly useful.
Ideally, a positive antibody test would tell you that you’ve recovered from COVID-19 or a coronavirus infection and have immunity from future infections, allowing you to return to work, travel, and socialization without the risk of transmitting the infection or becoming sick again yourself.
However, researchers don’t yet know whether the presence of antibodies means that you have immunity, whether you could still get sick from a different strain of the virus, or how long immunity lasts.
Diagnostic tests detect active infections. This is the test you want if you think you’ve been exposed to the coronavirus or are exhibiting symptoms of COVID-19.
There are currently two types of diagnostic tests available.
- The molecular real-time polymerase chain reaction (RT-PCR) test detects the virus’s genetic material.
The antigen test detects specific proteins on the surface of the virus.
- The RT-PCR nasopharyngeal tests are more widely used and more familiar. Most involve sticking a 6-inch swab deep into your nose to collect virus samples to test.